js 对象常用扩展

//js string对象扩展(function() { ???// 除去两边空白 ????String.prototype.trim = function() { ???????return this.replace(/(^\s*)|(\s*$)/g, ""); ???}; ???//截取字符串了 ????String.prototype.cutStr = function(len) { ???????var str = this; ???????var str_length = 0; ???????var str_len = 0; ???????str_cut = new String(); ???????str_len = str.length; ???????for (var i = 0; i < str_len; i++) { ???????????a = str.charAt(i); ???????????str_length++; ???????????if (escape(a).length > 4) { ???????????????//中文字符的长度经编码之后大于4 ?????????????????str_length++; ???????????} ???????????str_cut = str_cut.concat(a); ???????????if (str_length >= len) { ???????????????str_cut = str_cut.concat("..."); ???????????????return str_cut; ???????????} ???????} ???????//如果给定字符串小于指定长度，则返回源字符串； ?????????if (str_length < len) { ???????????return str; ???????} ???}; ???// 保留中文 ????String.prototype.getCn = function() { ???????return this.replace(/[u4e00-u9fa5uf900-ufa2d]/g, ""); ???}; ???// 保留数字 ????String.prototype.getNum = function() { ???????return this.replace(/[^\d]/g, ""); ???}; ???// 保留字母 ????String.prototype.getEn = function() { ???????return this.replace(/[^A-Za-z]/g, ""); ???}; ???//从右边截取，到终点字符位置 ???String.prototype.subIndexStr = function(str) { ???????var index = this.indexOf(str); ???????return this.substr(0, index); ???}; ???// 从左截取指定长度的字串 ????String.prototype.left = function(n) { ???????return this.slice(0, n); ???}; ???// 从右截取指定长度的字串 ????String.prototype.right = function(n) { ???????return this.slice(this.length - n); ???}; ???// HTML编码 ????String.prototype.HTMLEncode = function() { ???????var re = this; ???????var q1 = [/x26/g, /x3C/g, /x3E/g, /x20/g]; ???????var q2 = ["&", "<", ">", " "]; ???????for (var i = 0; i < q1.length; i++) ???????????re = re.replace(q1[i], q2[i]); ???????return re; ???}; ???//字符串转换为日期格式 ???String.prototype.toDate = function() { ???????if (isNaN(this) && !isNaN(Date.parse(this))) {　　 ???????????return new Date(this); ???????} else { ???????????console.error(this == null ? "不是日期格式" : this + "不是日期格式") ???????} ???}; ???//左边补零 ???String.prototype.padLeftZero = function(n) { ???????return Array(n > this.length ? (n - (‘‘ + this).length + 1) : 0).join(0) + this; ???}; ???//右边补零 ???String.prototype.padRightZero = function(n) { ???????return this + Array(n > this.length ? (n - (‘‘ + this).length + 1) : 0).join(0); ???}; ???//转换人民币格式 ???String.prototype.toRenminbi = function() { ???????var n = this.replace(/,/g, ‘‘);; ???????var fraction = [‘角‘, ‘分‘]; ???????var digit = [‘零‘, ‘壹‘, ‘贰‘, ‘叁‘, ‘肆‘, ‘伍‘, ‘陆‘, ‘柒‘, ‘捌‘, ‘玖‘]; ???????var unit = [ ???????????[‘元‘, ‘万‘, ‘亿‘], ???????????[‘‘, ‘拾‘, ‘佰‘, ‘仟‘] ???????]; ???????var head = n < 0 ? ‘欠‘ : ‘‘; ???????n = Math.abs(n); ???????var s = ‘‘; ???????for (var i = 0; i < fraction.length; i++) { ???????????s += (digit[Math.floor(n * 10 * Math.pow(10, i)) % 10] + fraction[i]).replace(/零./, ‘‘); ???????} ???????s = s || ‘整‘; ???????n = Math.floor(n); ???????for (var i = 0; i < unit[0].length && n > 0; i++) { ???????????var p = ‘‘; ???????????for (var j = 0; j < unit[1].length && n > 0; j++) { ???????????????p = digit[n % 10] + unit[1][j] + p; ???????????????n = Math.floor(n / 10); ???????????} ???????????s = p.replace(/(零.)*零$/, ‘‘).replace(/^$/, ‘零‘) + unit[0][i] + s; ???????} ???????return head + s.replace(/(零.)*零元/, ‘元‘).replace(/(零.)+/g, ‘零‘).replace(/^整$/, ‘零元整‘); ???}; ???String.prototype.amountFormat = function() { ???????var number = this; ???????var decimals = 2; ???????number = (number + ‘‘).replace(/[^0-9+-Ee.]/g, ‘‘); ???????var n = !isFinite(+number) ? 0 : +number, ???????????prec = !isFinite(+decimals) ? 0 : Math.abs(decimals), ???????????sep = (typeof thousands_sep === ‘undefined‘) ? ‘,‘ : thousands_sep, ???????????dec = (typeof dec_point === ‘undefined‘) ? ‘.‘ : dec_point, ???????????s = ‘‘, ???????????toFixedFix = function(n, prec) { ???????????????var k = Math.pow(10, prec); ???????????????return ‘‘ + Math.floor(n * k) / k; ???????????}; ???????s = (prec ? toFixedFix(n, prec) : ‘‘ + Math.floor(n)).split(‘.‘); ???????var re = /(-?\d+)(\d{3})/; ???????while (re.test(s[0])) { ???????????s[0] = s[0].replace(re, "$1" + sep + "$2"); ???????} ???????if ((s[1] || ‘‘).length < prec) { ???????????s[1] = s[1] || ‘‘; ???????????s[1] += new Array(prec - s[1].length + 1).join(‘0‘); ???????} ???????return s.join(dec); ???};})();//js ?Date 时间对象扩展(function() { ???Date.prototype.toString = function(fmt) { ???????function padLeftZero(str) { ???????????return (‘00‘ + str).substr(str.length); ???????} ???????if (/(y+)/.test(fmt)) { ???????????fmt = fmt.replace(RegExp.$1, (this.getFullYear() + ‘‘).substr(4 - RegExp.$1.length)); ???????} ???????let o = { ???????????‘M+‘: this.getMonth() + 1, ???????????‘d+‘: this.getDate(), ???????????‘h+‘: this.getHours(), ???????????‘m+‘: this.getMinutes(), ???????????‘s+‘: this.getSeconds() ???????}; ???????for (let k in o) { ???????????if (new RegExp(`(${k})`).test(fmt)) { ???????????????let str = o[k] + ‘‘; ???????????????fmt = fmt.replace(RegExp.$1, (RegExp.$1.length === 1) ? str : padLeftZero(str)); ???????????} ???????} ???????return fmt; ???}})();